Google just released the fourth developer preview of Android N for folks who are participating in the beta program. You can find the appropriate links to install the update below but, if you’re already enrolled and using the latest software, you should also simply get a notification to install Android N Developer Preview 4.
Like the earlier versions of the update, you’ll find support for the Pixel C, Nexus 9, Nexus 9 with LTE, Nexus 6P, Nexus 6, Nexus 5X, the Nexus Player and the General Mobile 4G (part of Google’s Android One program.) The Xperia Z3 has had access to the developer builds but that software is updated independently through the Xperia Companion software, so you’ll need to look for that update there (if it’s even available yet.)
No word yet on what’s new but we’ll try to look on our Nexus 6P for some changes.